Network Rail (NR) is to be prosecuted over the 2007 Grayrigg train crash in Cumbria in which one passenger died, it was announced today.

The Office of Rail Regulation (ORR) said it had started criminal proceedings against NR for a breach of health and safety law which caused a Virgin Trains Pendolino train to derail near Grayrigg on 23 February 2007.

Passenger Margaret Masson was killed and 86 people were injured, 28 seriously.

Earlier investigations as well as last year's inquest into the death of Masson concluded that the derailment was caused by a poorly maintained set of points.

NR is facing a charge under section 3(1) of the 1974 Health and Safety at Work Act.

The first hearing is due to take place at Lancaster Magistrates' Court on February 24. The maximum penalty a magistrates' court can impose for the offence is a fine of £20,000.

The ORR said: "This results from the company's failure to provide and implement suitable and sufficient standards, procedures, guidance, training, tools and resources for the inspection and maintenance of fixed stretcher bar points."

The stretcher bars hold the moveable rails a set distance apart when the points are operated.

The ORR railway safety director Ian Prosser said: "Following the coroner's inquest into the death of Mrs Masson, I have concluded that there is enough evidence, and that it is in the public interest, to bring criminal proceedings against NR for a serious breach of health and safety law which led to the train derailment."

NR network operations managing director Robin Gisby said: "The Grayrigg derailment in 2007, resulting in the tragic death of Mrs Margaret Masson, was a terrible event.

"Network Rail has not hidden from its responsibilities. The company accepted quickly that it was a fault with the infrastructure that caused the accident. We again apologise to Mrs Masson's family.

"Since the derailment, we have worked closely with the authorities, conducted comprehensive and detailed investigations and made substantial changes to our maintenance regime.

"Today there is no safer form of travel than rail and it is important that the rail industry seeks ways to make it safer still."

Last year, NR was fined £3 million at St Albans Crown Court after admitting safety breaches involving a set of points which led to a derailment at Potters Bar in Hertfordshire in May 2002. Seven people were killed.

NR had assumed responsibility for the crash from its predecessor rail infrastructure company, Railtrack.

The ORR delayed any decision on bringing its own prosecution over Grayrigg until the inquest into Mrs Masson's death concluded in November 2011 and after the Crown Prosecution Service (CPS) had said it would not bringing a prosecution.

Manuel Cortes, leader of the TSSA rail union, said: "We welcome this prosecution, although we are disappointed that it has taken five years for this to happen."